Mechanical fuse for artillery projectiles



1,642,520 pt. 13, A. VARAUD MECHANICAL FUSE FOR ARTILLERY PROJECTILES Original Filed May 13, 1924 Fig. 1.

'15 the regulating of the'time of ignition is'deframe of the clockwork in a cylindricalcas- V 35 ing of the fuse and the'inoment'offiring ing this frame in the interiorofthis fuse Patented Sept. 13, 1927. r 1,642,520

ries.

ANDRE VARAUD, or GENEVA,- SWITZERLAND, ASSIGNOR TO TAVANN'ES WATCH 00. s. A., or TAVANNES, BERN, SJVITZEBLAND, A CORPORATION or SWITZERLAND.

MECHANICAL FUSE FOR ARTILLER Y PROJECTILES.

Original application filed May 13, 1524, Serial ll'o. 712,960, and in Switzerland August 2, 1923. Divided and this application filed June 24, 1925. Serial No. 39,237.

of the type in which the release of the strikaXial direction. or device is controlled by a rotary member, This manner of mounting the clockwork the angular position of which can be regu in the body of the fuse is defective in that 5 lated priorfto tiring and which duringthe thenecessity for allowing thetiming memflight of the projectile isdriven by a clockber ,thelatitude of turning about'itself may work movement in a direction opposite to prevent the tightening ring employed for that in which it-is turned while being set. pressing the frame of the clockwork to the g It relates more particularly to the body of bottom of its cavity from being applied 60 sucha fuse, the' frame of thp clockwork with sufficient pressureto prevent any un- "movement and the manner in which this timely unscrewing of the ring during the frame is fixed .in the hollow body of the timing and any disruptingact-ion at the fuse, moment of the departure of the projectile. Asis custcmary'in the fuses of thistype Finally it; has been proposed to house the, 65

The invention refers to'mechanical fuses clockwork and this timing member in the termined by the angular displacement of the ing and to enclose this casing in the interior rotary timing member with regard to the of a hollow fuse'composed of two parts. body of the fuse and it is indispensable for This manner of mounting results, it is true, obtainingla precision of the firing that'any in obtaining a rigidity of the whole thus 70 relative movementbetween this rotary memformed by the body of the fuse and the her and the'body of th'e fuse is excluded frame of the clockwork sufficient to prevent once the timing of the fuse has taken place. any action on the departure of the projec- For obtaining this result in most of the tiletending to disturb the regulation of the fusesof this known type means are profuse but in practice itis very ditlicult to 210- 76 id d whi h are t d lik a w dge at complish this due tothe'fact that the casthe moment of the departure of the projecg ln fiQ ed i in One piece and due tile by the effects of inertia, in such a manto the absence of means for determining prener that the rotary member is wedged in clsely and very quickly the'relative angular the body of the fuse and thereby becomes posit-1011 respectively of the frame in reso rigidly fixed to the latter. 1 gard to the casing and of the latter in rein practice these means do however not g' t0 dy of the l. produce the-result aimed at and often a dis- Now accordingto this invention a body ,turbance takes place either during the loadof the fuse 1S provided, a frame of the clocking of the, projectile, since during the tim- WOI'k 0f Suchfi sefi d m thod of mountthese wedging means are inoperative, or body which is made of two parts screwed one 'atf'the momentof firing because these wedgupon the other, enabling all the above dismeans do not then render the timing advantages to be V y-fi p y" element-integral with the body of the fuse ment of a cylindrical casing made in two 44 with the requisite instantaneousness for pre Scull-cylindrical parts presenting at its peventing all disrupting actions at the moment phery lOngltudinal projections on diametof the angular inertia of the said timing elerically opposite sides which cooperate with ment. grooves correspondingly provided in the In other fuses of this known type, it has body of the fuse, thereby preventing any 45 been proposed to house the frame of the angular displacement of the casing in regard clockwork in a cylindrical cavity provided tothe said body. in the body of the fuse, and to provide the The drawing illustrates by way of exrotatable timing member with a supporting ample a constructional form of this inven surface and a tightening ring bearing theretion applied to a mechanical fuse of the so on which is screwed into the entry of this type described in my co-pending application cavity so as to immobilize the frame of the Serial No. 712,960 filed May 13, 1924, also in application, Serial No. 37,608, filed June 17, 1925, and Serial No. 38,4:98 filed June 20,

Fig. 1 is an axial section of a fuseembodying my present invention.

Fig. 2 is a transverse section taken on the l-ine A-A,of Fig, 1, and;

Figs. 3 and 4 are respectively detail views illustrating elevations of the exterior and interior of one half of the casing.

In the drawing fuse are not shown'because they do not form part of the actual invention and theirillustr ation seems unnecessary for the understanding of the object of the latter.

. In ,thedrawing l and 2 indicate the two parts of the hollow body of the fuse whlch are s'crewed oneto thegother so .as to house in}; longitudinal grooves interior of said fuse body.

proj ectionsbetweenthem the cylindrical casing 28.- This 'latteris formed in two semi-cylindrical parts presenting eachfone an outer longitudinal projection or rib 33. hen the two halves of the casing are united, these two projections assume diametrically opposite positions and engage at the moment of the mounting of the frame of the clockwork into the body of the fuse, with two cor-respondprovided in the .These grooves and these corresponding 33 constitute a kind of dove-tail arrangement between the casing and the body "of the fuse which on the one hand prevents any angular relative displacement between these two members, and on the other hand, does away with any uncertainty in the mounting for determining the angular relative position of the two members.

-Arr'anged in the two longitudinal sections of the casing 28 re-inforce d by thev projections 33 are notches adapted to be engaged by corresponding 'tenons formed on the periphery of'three transverse plates 29 upon and between which the movable parts of the clockwork are spaced and secured.

These plates 29 are housed .in circular grooves provided in the interior wall of the casing =28'so as to form an absolutely rigid unit with the casingand with three discs 30, 32 and 31 superposed one to the other and which constitute the compact bottom of the clockwork frame. vThe outer .discsQO and the movable parts of the 31 are fitted to the casing with the aid of dia metrically opposed screws, whilst the inter-' mediary disc like the plates above referred to, is provided with two diametrically opposed projectionseng'aging with two corresponding notches in the casing.

.This disc 32 is a steel washer serving to reinforce the :bottom :oft-he frame of the clockwork while the disc is hollow in order to serve as a barrel forreceivmg the power spring of the clockwork.

The advantages of the fuse body as shown in the two last constructional forms are the following ones:

" ,Firstof all it is possible :to make only the shoulder from a'sufiiciently hard metal (steel or 'brassl for resisting the shocks due to inertia, it being posslble tomake the cap of the fuse of aluminum in order to reduce the total weight of the fuse, which constitutes an advantage which is highly valued in the exterior ballistics.

On the other hand these constructional forms mal zesit possible to simplify the finishing .ofthehollow body of the fuse in which it is not necessary to have as precise dimensions asin the case of the first form in which it is the fuse itself and not onlya shoulder which is directly assembled with the clockluble direction'by means of tenons and notches.

'3. A fuse as per claim 1, in which the rear part of the frame is constituted by three superposed disks rigidly connected Withtl'ie casing by means of a unison effected by tenons and notches and by means of screws.

In testimony whereof I. afiix. my signature.

ANDRE. VARAUD. 

